Furnace.



Patented July 16, l90l.

F. J. KUHLMANN.

FU R N A C E.

(Application filed May 6, 1901.)

2 Sheik-Sheet I.

(No Model.)

51 u um 1 to z 6H0: we Ida THE NQHRIS PETERS 00., PNOTO-LITNO. WAQNINGYON DV C.

2/0 H use:

Patented luly l6, I901. nu. KUHLMANN.

FU RNAC E. (Application filed May a, 1901.

2 sheets-sum 2,

9 Model.) *5

amm iw 1 $0 UNITED STATES PATENT Erica. 1

FREDERICK J. KUHLMANN, OF CINCINNATI, OHIO.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 678,499, dated July 16, 1901.

Applicationfiled May 6, 1901.

T0 ctZZ whom, it may concern:

Be it'known that I, FREDERICK J. KUHL- MANN, a citizen of the United States of America, and a resident'of Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Furnaces, of which the following is a specification.

The object of my invention is a means of producing perfect combustion of fuel within the furnace and preventing the production of smoke. This object is attained by the means described in the annexed specification and illustrated in the accompanying drawings, in which Figure l is a front elevation of a furnace supplied with the improvements embodying my invention, the boiler, steam-drum, and grate-bars being shown in dotted lines. Fig. 2 is a detail sectional view of the front part of the furnace. Fig. 3 isa detail view of one of the jets which are located in the front wall of the furnace above the grate-bars. Fig. 4 is a vertical transverse sectional view taken upon line 1; c, Fig. 1, the top of the boiler being shown broken away. Fig. 5 is a vertical sectional view taken upon line y y of Fig. 4;

looking toward the rear of the furnace.

Referring to the parts, near the front of the furnace, in the side walls aa thereof, are inserted channels or pipes B B, which lead into the furnace above and below grate-bars a the point above the grate-bars being at a distance from them such that it may be above the fuel on them. Pipes B and B are connected beneath the grate-bars with pipes C G, which run thence beneath the grate-bars and adjacent to the walls a a rearwardly to points adjacent to bridge-wall a Pipes 0 C are connected by a pipe G which runs adjacent to the bridge-wall beneath the grate-bars. Bridge-wall a is surmounted by a tiling or roof at, which projects forward over the fire. A series of vertical channels a are formed in the bridge-wall, running from points beneath the grate-bars opposite pipe 0 to points above the grate-bars beneath roof a Within the channels a? are reduced pipes c,w'hich are tapped into" pipe C and project into the furnace above the fire. Leading from steamdrum d of boiler D down in front of the furnace is a vertical pipe (1, which has at its lower end branch pipes 01 (:2 which have in- Serial No. 68 907. (No model.)

jectors E E leading into pipes O 0 just be= yond the points where pipes B B are connectedto them. Pipe d has also above furnacedoors 01, a horizontal branch pipes 01 d from which jets 01 project through the front wall of the furnace above the points at which pipes B B enter the furnace. Jets'd have valves d and pipe d has valves 01 and d to control the flow of steam through them.

In operation the steam-valves are opened to admit steam from the steam-drum through pipe d to jets d and injectors E and E. The steam issuing from the'injectors sucks the colder and heavier gases from the front of the furnace down through pipes B and B and conveys them back through pipes C, O, and C and injects them out through pipes c beneath the roof a of the bridge-wall over the hottest part of the fire. The force with which they issue through pipes 0 draws a plentiful supply of oxygen into the fire'from the rear of I the ash-pit, where the air is warmest, through channels a The roof of the bridge-wall directs these gases issuing from pipes c and the air from channels a down over the hottest part of the fire, producing the conditions most favorable to perfect combustion of the gases-viz., a high temperature with a thorough intermingling of the gases with heated oxygen. Jets (1 project steam over the fire fromthe front part of the furnace back heneath roof at This steam holds the gases down toward the fire that they may be most highly heated and also assists in keeping them around the mouth of pipes B and B, so that they are drawn into them.

What I claim is 1. In a furnace the combination of a channel leading from a point above the fire in the front part of the furnace down beneath the grate-bars, a pipe into which said channel leads running rearwardly beneath the gratebars to the bridge-wall, a second pipe adjacent to the bridge-wall coupled to said pipe, reduced pipes leading from said pipe up above the fire and directed back over the fire, a steam-pipe to convey steam from the boilers, and an injector connecting the steam-pipe and the pipe leading from the channel rearwardly, substantially as shown and described.

2. In afurnace the combination of a bridgewall having a roof projecting forward over the fire, a pipe leading from a point above the fire in the front part of the furnace to a point beneath the grate-bars, a second pipe coupled to said pipe beneath the grate-bars running rearwardly to the bridge-wall and bent to run adjacent to the bridge-wall, contracted pipes connected to said second pipe running up through said bridge-wall and out over the fire beneath the roof thereof, a steam-pipe leading from the boiler, and injectors connecting the steam-pipe and said second pipe, substantially as shown and described.

3. In a furnace the combination of a chan nel leading from a point above the fire in the front part of the furnace down beneath the grate-bars, a pipe into which said channel leads running rearwardly beneath the gratebars to the bridge-Wall, a second pipe adjacent to the bridge-wall coupled to said pipe, reduced pipes leading from said pipe up above the fire and directed back over the fire, a steam-pipe to convey steam from the boilers,

an injector connecting the steam-pipe and 

